Determination of atmospheric isocyanate concentrations by high-performance thin-layer chromatography using 1-(2-pyridyl)piperazine reagent

Abstract

A high-performance thin-layer chromatographic method is described for the determination of both aliphatic and aromatic isocyanates and their oligomers in air. The test atmosphere is drawn through a 2 × 10^–4M solution of 1-(2-pyridyl)piperazine in toluene at a sampling rate of 1 l min^–1 for 5–20 min. The sample solution is concentrated to 100 or 200 µl of which 1–5 µl are applied to a thin-layer plate, eluted and detected with iodoplatinate reagent. The sample spots may be measured visually or using a scanning densitometer. Concentrations down to 0.0003 p.p.m. (2 µg m^–3) can be determined.